ANEURINE (thiamine) 



is employed. If such an organism is grown on a medium containing 

 aneurine, the amount of gas produced is, within limits, proportional 

 to the aneurine concentration. The chief disadvantage, already 

 referred to, is that other substances may be present that stimulate 

 the fermentation. Such substances are said to be present in urine, 

 and both the thiazole and the pyrimidine moieties of aneurine enhance 

 gas production. The organisms used in this microbiological method 

 of assay were certain strains of Saccharomyces cerevisiae : but not all 

 yeasts, and not even all Saccharomyces, require added aneurine before 

 growth occurs. In an examination of thirty-six kinds of yeast, P. R. 

 Burkholder ^ found that fifteen kinds required aneurine, whilst of a 

 further thirty-three yeasts examined by P. R. Burkholder and D. 

 Moyer,* twenty-four required aneurine. The most marked deficiencies 

 were observed with Candida suaveolens and C. deformans, Chalara 

 mycoderma, Mycoderma lipolytica, M. valida and M. vini, Pichia belgica 

 and P. Drombrowskii, Saccharomyces fragilis, S. globosus, S. macedo- 

 niensis, S. muciparus, S. validus, Saccharomy codes ludwigii, Torulopsis 

 laurentii, T. dattila and Zygosaccharomyces mandshuricus. In a third 

 paper, Burkholder and his colleagues ^ examined no further species 

 and varieties of yeast and found that thirty-three required aneurine. 

 These comprised strains of the following additional species : Sac- 

 charomyces cerevisiae var. ellipsoideus, Kloeckera brevis, Zygosaccharo- 

 myces japonicus, Z.priorianus and Torulopsis stellata. K. brevis was of 

 particular interest, as it responded to six different vitamins. Emery 

 et al.^ confirmed the observations of Burkholder et al. regarding the 

 requirement of S. macedoniensis and K. brevis for aneurine, and used 

 the former for assaying aneurine, whilst A. S. Schultz and L. Atkin' 

 confirmed the need of other yeasts for aneurine. Additional species 

 for which aneurine was found to be essential were ^ Saccharomyces 

 hanseniaspora valbyensis and 5. galactosus. For the latter, aneurine 

 could be replaced by a mixture of the thiazole and pyrimidine halves, 

 but the former required the intact vitamin. 



Pyruvic acid was formed in a medium inoculated with a yeast 

 deprived of aneurine and incubated for twenty-five hours. On addi- 

 tion of aneurine, the pyruvic acid disappeared.^ 



Most yeasts — those grown commercially at all events — synthesise 

 aneurine, especially if the thiazole moiety is added to the culture 

 fluid. For instance, the aneurine content of bakers' yeast was in- 

 creased from 20 or 30 to 200 /xg. per g. of dry weight by addition of 

 the thiazole compound to a wort agar.^*^ The factors affecting the 

 accumulation of aneurine in the cells of various kinds of yeast were 

 studied by H. Fink and F. Just and their colleagues. ^^ They found 

 that the normal metabolism of brewers' yeast, growing in a medium 

 containing aneurine, was disturbed by aeration, resulting in a lower 



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